Global vertebrate populations have fallen by 60 per cent since 1970 as human activity destroys their natural habitats in grasslands, forests, waterways and oceans, the organisation said in the Living Planet Report 2018.

"The situation is really bad, and it keeps getting worse", WWF International director general Marco Lambertini told AFP.

"The only good news is that we know exactly what is happening".

Tropical areas have seen the worst declines, with an 89% fall in populations monitored in Latin America and the Caribbean since 1970.

"From the decline of orangutans due to deforestation for palm oil to the ruinous impact of climate change on Arctic habitats to plastic pollution destroying marine wildlife, we can not continue with business as usual", he added.

Conservationists are making demands for urgent worldwide action after a major report uncovered an unprecedented crisis in nature that threatens to devastate the world economy and imperil humanity itself.

Worldwide action is needed over the next two years in order to stem the tide of natural destruction, the organization noted, urging world governments and businesses to strike a deal similar to the 2016 Paris agreement for climate change.

The pace of population increase - long taboo in development and conservation circles - also took off around 1950, the date scientists have chosen as the "gold spike", or starting point, for a new geological period dubbed the Anthropocene, or "age of man".

"If we want a world with orangutans and puffins, clean air and enough food for everyone, we need urgent action from our leaders and a new global deal for nature and people that kick starts a global program of recovery", Steele said in her statement.

In looking for answers, conservationists are turning to climate change for inspiration.

"One was the realisation that climate change was unsafe for the economy and society, not just polar bears", he said.

Ten thousand years ago that ratio was probably reversed.

"A healthy, sustainable future for all is only possible on a planet where nature thrives and forests, oceans and rivers are teeming with biodiversity and life", he said.

The Paris Agreement, negotiated under the United Nations convention on climate change, also set a clear target: Global warming must be held to "well below" 2 deg C, and 1.5 deg C if possible.

African elephant populations in Tanzania have declined by 60% between 2009 and 2014, mostly due to poaching for their ivory.

Deforestation in Borneo, created to make way for timber and palm oil plantations, led to the loss of 100,000 orangutans between 1999 and 2015, the report estimated.